How to machine plane Cupping on timber boards
Woodworking machinery used: Planner Thicknesser
An alternative that seems to work is:
1. With the convex side up, take gentle passes through the thicknesser until a strip approximately half the full width is flattened.
2. Now flip it over so the concave side is facing up and do the same.
3. From here until you have the right thickness keep on flipping it over.
By flipping it once you have a flat area, the problem of the thicknesser rollers pressing it flat is reduced.
That covers the basics, any compound problems can be tackled with combinations of the techniques. Use accurately set woodworking machinery in combination with simple flat straight jigs.
If you fancy a practice job, try making a “Jenga” set, see what difference it makes to the stability of towers when you change the moisture content.